MEMS device and method of manufacturing a MEMS device

• US 10,384,934 B2
• Filed: 03/16/2018
• Issued: 08/20/2019
• Est. Priority Date: 10/12/2012
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Dehe, Alfons, Pindl, Stephan, Knott, Bernhard, Ahrens, Carsten
• Primary Examiner(s): Inoussa, Mouloucoulaye
• Application Number:
  US15/923,599
• Publication Number:
  US 20180201504A1
• Time in Patent Office: 522 Days
• Field of Search: 257415, 257E29324, 257E2104, 257416, 257E29, 257E21, 438694, 438 52, 438 14, 438 53, 438 51
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81C 1/00825 Protect against mechanical threats, e.g. against shocks, or residues B81C1/00261 take precedence
• CPC Class Codes: B81C 1/00873 characterised by special arrangements of the devices, allowing an easier separation
• CPC Class Codes: B81C 2201/017 Methods for controlling internal stress of deposited layers not provided for in B81C2201/0164 - B81C2201/0169
• CPC Class Codes: B81C 2201/053 Depositing a protective layers
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005
• CPC Class Codes: H04R 31/00 Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182

Abstract

A method for manufacturing a MEMS device is disclosed. Moreover a MEMS device and a module including a MEMS device are disclosed. An embodiment includes a method for manufacturing MEMS devices includes forming a MEMS stack over a first main surface of a substrate, forming a polymer layer over a second main surface of the substrate and forming a first opening in the polymer layer and the substrate such that the first opening abuts the MEMS stack.

Claims

1. A method for manufacturing microelectromechanical systems (MEMS) devices, the method comprising:

forming a MEMS stack over a first main surface of a substrate;

forming a polymer layer over a second main surface of the substrate;

forming a first opening in the polymer layer such that the first opening overlaps with the MEMS stack;

forming a second opening in the polymer layer while forming the first opening in the polymer layer;

filling the second opening with an etch stop material to cover the polymer layer; and

with the etch stop material covering the polymer layer, etching the substrate to extend the first opening into the substrate such that the first opening exposes a surface of the MEMS stack.

2. The method according to claim 1, further comprising performing a release etch to form moveable components of the MEMS devices.

3. The method according to claim 2, performing the release etch comprising etching with HF based chemistry.

4. The method according to claim 2, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes all of the sacrificial layer.

5. The method according to claim 2, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes a substantial portion of the sacrificial layer leaving spacers.

6. The method according to claim 1, wherein the polymer layer is a negative photoresist.

7. The method according to claim 1, wherein the polymer layer is a positive photoresist.

8. The method according to claim 1, further comprising cutting the substrate to form individual MEMS devices without removing the polymer layer.

9. The method according to claim 8, wherein the cutting is aligned with the second opening.

10. The method according to claim 8, wherein the etch stop material comprises a hard mask.

11. A method for manufacturing microelectromechanical systems (MEMS) devices, the method comprising:

forming a MEMS stack over a first main surface of a substrate;

thinning the substrate to expose a second main surface;

forming a polymer layer over the second main surface;

patterning the polymer layer to form a first opening and a second opening, wherein the first opening overlaps with the MEMS stack;

filling the second opening with a masking layer to cover the polymer layer;

with the masking layer covering the polymer layer, extending the first opening into the substrate such that the first opening exposes a surface of the MEMS stack;

removing the masking layer after exposing the surface of the MEMS stack; and

performing a release etch to form moveable components of the MEMS devices.

12. The method according to claim 11, wherein performing the release etch comprising etching with HF based chemistry.

13. The method according to claim 11, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes all of the sacrificial layer.

14. A method, for manufacturing microelectromechanical systems (MEMS) devices, the method comprising:

forming a MEMS stack over a first main surface of a substrate;

thinning the substrate to expose a second main surface;

forming a polymer layer over the second main surface;

patterning the polymer layer to form a first opening and a second opening, wherein the first opening overlaps with the MEMS stack;

filling the second opening with a masking layer to cover the polymer layer;

with the masking layer covering the polymer layer, extending the first opening into the substrate such that the first opening exposes a surface of the MEMS stack;

removing the masking layer after exposing the surface of the MEMS stack; and

Performing a release etch to form moveable components of the MEMS devices, wherein the MEMS stack comprises a sacrificial layer disposed between a backplate and a membrane, and wherein the release etch removes a substantial portion of the sacrificial layer leaving spacers.

15. The method according to claim 14, wherein performing the release etch comprising etching with HF based chemistry.

16. The method according to claim 14, wherein the polymer layer is a negative photoresist.

17. The method according to claim 14, wherein the polymer layer is a positive photoresist.